Lubricating grease composition



rallied ,July 12,1949

2.475.589 LUBarcA'rnvG caress conrosrnog Arnold A. Bondi, San Francisco,Calif., assignor to Shell Development Company, San Francisco, Calif., acorporation of Delaware No Drawing. Application April 18, 1947,

\ Serial No. 742,467

21 Claims. (Cl. 252-42) 1 This invention relates to novel, greases andto processes for the preparation thereof. More particularly, thisinvention P tains to a novel method of making and rapidly coolingsoap-containing greases so as to produce.

an oxidation and water resistant, non-bleeding soap-containing greasehaving outstanding mechanical stability and thermal reversibility. Thisis a continuation-in-part of the co-pending application Ser. No.666,790, filed May 2, 1946.

It is well known in the art that certain alkali, alkalineearth and heavymetal ,soap greases are valued for their water resistance and stableconsistency over wide temperature ranges. However greases of this typeare extremely difficult to improved The conventional method of makinggreases is to charge a calculated amount'of soap of between about 5% andabout 25%, or higher, into a suitable grease kettle and to add theretoabout half of the required amount of oil. The oil-soap mixture is thenheated to around about 350 F. to

450 F. with agitation until a homogeneous mass is obtained. The balanceof the oil is then slowly added, with stirring. Stirring. is continueduntil a homogeneous mass is formed atwhich time the grease is allowed tocool either inthe grease kettle or @in pans to the ambient-temperature.Some greases thus formed are generally lumpy and require reworking bymilling or homogenizing to produce due to the fact that the resultantproddots are not homogeneous and bleed profusely. Bleeding is primarilydue to the fact that the non-aqueous soaps have a marked tendency tosynergize, thereby causing a separation of the soap from the oil inwhich it is dispersed. Slow cooling aggravates this condition and inaddition forms a product which is heterogeneous in structure. This isdue to the fact that a very stiff product forms on the surface whichinhibits further heat dissipation from underlying layers of the hotgrease, resulting in a product which is 'hard at the surface but issoft, semi-liquid or even liquid at the center.

Greases of the type under consideration are extremely sensitive to rapidcooling from a hot fluid state to a solid grease state. Rapid cooling ofsuch greases by present known methods results in the formation of falsebodies and lumps in the grease which bodies disintegrate under pressureand cause the grease to bleed.

Generally, to inhibit bleeding and improve the textu e of such greasesnumerous precautionary meas res are taken, such as extensive working ofthe grease in special homogenizers, e. g. the Cornell homogenizer. Suchprocedure is usually time consuming and adds greatly to the cost of thegrease. Other ways of producing stable, non-bleeding greases have beenattempted by either reducing ,the soap content generaly to less thanabout 5% by weight, or by increasing the soap content to a maximum.These methods of stabilizing greases against bleeding have alsoproved-to be unsatisfactory because in the case of reducing the soapcontent to less than 5%,, such greases become limited in their use dueto the low soap content. while increasing the soap content to a maximummakes the grease too costly and such products generally possess anundesired consistency.

produce a smooth and relatively stable grease.

It is an object of this invention to produce greases having goodmechanical stability and thermal reversibility. It is another object ofthis invention to produce greases by rapid cooling whereby greases, ofimproved smoothness and consistency are obtained. Still another objectis to produce non-bleeding greases. A further object is to provide amethod of making and cooling greases whereby milling or homogenizingsaid grease is not essential in producing a stable homogeneous product.Furthermore, it is an object of this invention to produce generalallpurpose industrial non-bleeding greases containing a minimum amountof soap.

The above and other objects may be attained in accordance with thepresent invention by admixing, with a suitable base oil, a soap madewhich can be evenstill further improved by addition to such greases ofcertain anti-bleeding agents and/or by rapid cooling by the method whichwill hereinafter be fully described. Rapidly chilled greases of thisinvention can be, if desired, homogenized to further improve theirtexture, consistency, stability and/or appearance.

The two fattymaterials used to form soaps of this invention are hydroxyfatty acids and hydrogenated fatty materials, preferably hydrogenatedfish oil fatty acids having at least 10 carbon atoms and up to -about 32carbon atoms and preferably between about 14 to 22 carbon atoms.

The hydroxy fatty acids may be naturally occurring or may be preparedfor example by taking estates 3 a suitable fatty acid and oxidizingit inan alkaline solution with potassium permanganate or other oxidizingagents. If potassium permanganate is used, aqueous sulfurous acid isadded to dissolve the precipitated manganese dioxide. ihe hydroxy acidscan be recovered from the precipitate by treatment with a suitablesolvent such as a low boiling naphtha. The undissolved hydroxy acids canbe removed with the aid of ether and recovered therefrom and purified byrepeated recrystallization with alcohol. Any hydroxy acids remaining inthe filtrate can be recovered by neutralizing it, evaporating it down toabout half its volume and acidifying it. The hydroxy acids are thenrecovered using ether and alcohol in the manner described. Other methodsof producing hydroxy fatty acids may be used such as digesting bromo'derivatives of unsaturated fatty acids with silver hydroxide or byheating chlorinated fatty acids under pressure with alkalis, alkalinecarbonates, etc. Specific hydroxy fatty acids applicable for use in thisinvention are dimethyl hydroxy caprylic acid, dimethyl iiydroxy capric,hydroxy physetoleic acid, ricinoleic acid, ricinelaidic acid, 12-hydroxystearic acid, 9,10 dihydroxy stearic acid, linusic acid, sativic acid,dihydroxy gadoleic, hydroxy behenic acid, quince oil acid and the like.The preferred hydroxy fatty acids are those in which the hydroxy groupis at least 12 carbon atoms removed from the carboxyl group.

The other fatty material which is used in admixture with the abovehydroxy fatty acids are hydrogenated animal, vegetable, fish oils andtheir derivatives. ated fish oil fatty acids containing from about 14 to22 carbon atoms derived from codfish oil, codliver oil, dogfish oil,dolphin fish oil, herring oil, Jap fish oil, menhaden oil, porpoise bodyoil, salmon oil, sardine oil, seal oil, shark oil, sperm oil, whale oiland the like.

Hydrogenation of these fatty oils and their derivatives, e. g. fattyacids, may be carried out by any known method preferably in the presenceof a suitable. catalyst and at an elevated temperature not exceeding 200C. genated fish oil fatty acids can be obtained by splitting the oil toproduce glycerine and fatty acids. After separation of the glycerine,the fatty acids can be hydrogenated or the hydrogenated fraction can besubjected to distillation thus splitting the fraction into two partsnamely an overhead distillate and residue fraction both of which can beused. The residue fraction can be subjected to-further splitting, theglycerine removed and the fatty acids hydrogenated and submitted to adistillation treatment. Various distillate and residue fractions can becombined or each fraction can be used separately. Instead of firstsplitting the fish oil and then hydrogenating the fatty acid fractions,the oil can be hydrogenated first and then split or the fish oil can besimply hydrogenated and used as such.

Analysis of typical hydrogenated fish oil fatty acids and theirderivatives which are particularly suitable as one of the components ofthe soaps of this invention are:

Example 1 2 8 4 Melting Point, 130 145 134 Saponiflcation Value. 190 194190 199 imiiiiiaq Value 3.6 23. c o 194 188 1 9 Titre "O 52 4 i Therange'of fatty acid mixture concentration Preferred are the hydrogen-Hydrod in greases of this invention varies from about 10% of a hydroxyfatty acid and 90% hydrogenated fatty oil and/or its fatty acidderivatives to about 90% of a hydroxy fatty acid and 10% hy- 5drogenated fatty oil product and preferably it is desirable to keep thehydroxy fatty acid in the range of between about to 90% by weight. Theproportions used are governed in part by the type of mineral oil baseused for compound- 10 ing the grease as well as its intended use.

The two fatty acids can be saponified with a suitable saponifying agentby any conventional method to form the soap. Thus soaps may be made bysaponification of various mixtures of the two fatty acid materials ofthis invention with alkali, alkaline earth and heavy metal oxide orhydroxide, and if desired, in the presence of oxides or hydroxides ofone or several of the above enumerated metals. Specific metal ions whichcan be chosen to form soaps of this invention are sodium, lithium,cesium, rubidium, calcium, strontium, barium, cadmium, zinc, aluminum,lead and the like. The soaps and their greases should be neutral,although they may be 25 slightlyalkaline or slightly acidic withoutdeviating from their remarkable mechanical stability; Whether the soapis made slightly alkaline or acidic depends primarily upon the intendeduse of the grease. For example in the case of lithium 0 soap care shouldbe exercised that the alkalinity of the soap does not exceed theequivalent of 0.2% lithium hydrate or its acidity exceed 0.5% stearicacid equivalent, the preferred range being from about 0.05 to 0.5%respectively. In cases where this range is exceeded. instability,bleeding and breakdown of grease structure might result. Instead ofmaking the soap first, it can be made in situ while making greases-ofthis invention.

The amount of soap which is used to make a grease of this invention mayvary from about 5% to about 25%, the preferred range being from about 8%to about 14% by weight.

Stabilizing and grease improving additives can be admixed in minoramounts with grease compositions of this invention at any time before,during or after its formation. Particularly desired are additives whichpossess the property of inhibiting bleeding of said greases andrendering them mechanically stable and thermally reversible. Materialswhich possess these properties are the alkali and alkaline earth metalsalt of a saturated cyclic hydrocarbon carboxylic acid such as sodium,lithium, calcium, barium, strontium and magnesium naphthenates; thealkylene glycol and/or alkylene thioglycol polymers as well as theirmono-esters and ether polymeric derivatives. The alkylene glycolpolymeric materials can be represented by the following generalstructural formula: HO-(R-O-RMOH wherein n is an integer and R isa'hydrocarbon radical 5 be such that the factor n times the number of.

carbon atoms in the R symbols should be at least 6 and more.

The polymeric alkylene glycols can be made by polymerizing in thepresence of a catalyst such 7 as iodine, hydriodic acid and the like,ethylene,

propylene, isobutylene, n-butylene oxides and/or their mixtures. Suchpolymers can also be produced by reacting a. monohydric alcohol with analkylene oxide. Thus a suitable product can be. made by reactingn-butanol with propylene oxideform the esters.

at between about 100 to 110 C. under pressure and in the presence of analkali catalyst.

The polymerized higher polyalkylene glycols having between 2 and 6carbon atoms in the alkylene group are most effective as additives ofthis invention and those containing the ethylene and propylene groupsare preferred. The 'average molecular weight of the polyalkylene glycolsmay be from about 200 or 400 to about 7000 and the preferred molecularweight being from about 1000 to 4000. a

It is desired to point out that the higher polyalkylene glycols arecomposed of mixtures of several polymers, for example, a polyethyleneglycol having an average molecular weight of 400 consists of variousglycols varying from a minor amount of monoethylene glycol andincreasing up to the pentadecaethylene glycol. Therefore,

it is the average molecular weight which is specitween 1 to about 22carbon atoms and preferably between about 10 to 18 carbon atoms. Acidswhich may be used are the aliphatic, aromatic, cyclic, sulfonic acidsand the like. Fatty acids and especially the higher fatty acids arepreferred and include such acids as lauric, myristic, palmitic, stearic,arachic, behenic, oleic, ricinoleic,

hydroxy stearic, phenylacetic, phenyl stearic acids and the like.However, such acids as naphthenic acid; oil-soluble petroleum sulfonicacids; tall oil fatty acids; aromatic acids, e. g. salicylic andphthalic acids and the like may be used to Specific examples of estersof this type are the polyethylene glycol monostearate, polyethyleneglycol monooleate and the like.

Ether derivatives of polyalkylene glycols may be made by anyconventional method and the aromatic ethers of polyalkylene glycolshaving the general formula wherein Ar is an aromatic radical havingattached thereto at least one alkyl radical denoted by R having from 1to about 8 carbon atoms and wherein Y is a fatty acid derivative, 71 isan inte-' ger and m is a number selected from the group consisting ofzero or 1.

Thio alkylene glycol polymers can be represented by the general formula:

wherein m, n and r are integers and R is an organic radical, preferablya hydrocarbon. These glycol or an alkylene oxide with an alkylenesulfide, e. g. ethylene, propylene, amylene sulfides, thio glycol ormercaptans.

.- materials can be prepared by reacting an alkylene The averagemolecular weight of the polyal- The amount of polyalkylene glycolderivatives thereof or other antibleeding agent which can be useddepends upon the soap concentration and in part upon the type of oilbase used. However it has been found that it is not necessary to usemore than 1% by weight of these additives although largr amounts can beused if desired. Generally effective results are obtained withconcentrations ranging from 0.01 to about 0.5% and preferably when keptwithin the range of between about 0.05 to about 0.25% by weight.

In accordance with the present invention the polyalkylene glycols and/ortheir derivatives can be added to the grease at any time during or afterthe cooking operation. The resulting grease may be cooled at anextremely rapid rate by the method which will hereinafter be describedor by any other rapid means of cooling without having any deleteriouseffect on the physical or chemical properties of the grease, but ratherimproves its mechanical stability, renders it thermally reversible andinhibits bleeding.

The mineral oil used for compounding said grease may be of wideviscosity range varying from 150 Saybolt Universal Viscosity at 100 F.to about 2000 Saybolt Universal Viscosity at 100 F. The viscosity indexof the oil can vary from below zero to about and have an averagemolecularweight ranging from about 250 to about 600. It may be highlyrefined and solvent treated by any known means. A preferred mineral oilis one which has a viscosity between about 300 to 700 'SUS at 100 F., aviscosity index of between about 40 to 70 and an average molecularweight of between about 350 to 550. The mineral oil may constituteanywhere from about 50 to by weight of the grease composition.

Highly desirable greases may be prepared by using formulations withinthe following range:

Per cent byweight A soap made from a mixture of a hydroxy fatty acid anda hydrogenated fatty oil and/or its derivatives Polyalkylene glycoland/or its derivatives 0.01 to 1 Hydrocarbon oil (viscosity 150-2000 S.S. U. at F.) 50 to 95 The grease can be prepared by dispersing acalculated amount of a soap of this invention in an oil base and heatingthe mixture at a temperature of between about 370 to about 450 F. untila homogeneous mass isobtained. If desired a modicum of a polyalkyleneglycol and/or its derivative, a metal naphthenate or other antiing thecooling period about 5 minutes and less than 15 minutes.

In order to illustrate the present invention more clearly, the followingexamples are presented. It is to be understood, however, that variousmodifications can be resorted to'without departing from the spirit ofthe invention as presented in the subioined claims.

Example IA In a suitable grease-making kettle approxi- "rnately 3.7% ofhydrogenated fish oil fatty acids and 3.7% of hydrogenated castor oilfatty acid, 1.0% lithium hydrate solution and about 10% of amuse a 100S. U. S. at 100 F. paraflln oil were admixed and heated while stirringto a temperature of between about 380 11'. and about 400 F. Anadditional amount oi! about 50 to 55% of 100 When a homogeneous mass wasformed about 0.01 polyethylene glycol was added to the grease. The hotfluid mass was poured into fiat pans to a depth of less than 1 inch andexposed to 0. current of cooling air so that the grease cooled down toaround about 150 F. in less than 30 minutes. The cooled grease wasmilled to form a more improved non-bleeding lithlum'soap grease.

Example '18 The process of making the grease of Example IA was repeatedexcept that the polyethylene glycol was omitted.

Example "A A grease of this invention was made by admixing approximately3.4% of a hydrogenated fish oil fatty acid, 7.0% of 12-hydroxy stearicacid, 1.6% of lithium hydrate and 12% of 100 S. U. S. at 100 F. parafllnoil and heating said mixture to form a homogeneous mass. To it,approximately 50% v Example HE A grease was made in the same manner asdisclosed in Example IIA except that polyethylene glycol was omitted.

Example [II A grease having the following formulation was cooked in aconventional manner, and subsequently pumped in a thin stream onto acooling belt where it is chilled from about 380 F. to about 200 F. orless within minutes. The chilled grease is then broken up by a screwconveyor and pumped through 80 mesh screens into an agitator equippedtank, where it is stirred for about 4 hours and pumped from therethrough mesh or finer screens to a storage tank.

Composition of grease: Percent 12-hydroxy-stearic acid 8 Hydrogenatedfish oil fatty acid 2 Lithium hydrate 1.52

100 SUS at 100 F. paraflln base oil..-" 27 2000SUS at 100 F.naphthenebase oil- 63 Polyethylene glycol (molecular weight Example IVAApproximately 8 to 10% by weight of a sodium soap prepared by reactingin about 10% by weight of 100 SUS at 100 F. Coastal pale oilapproximately equal parts by weight of 12 hydroxy stearic acid and ahydrogenated fish oil fatty acid with metallic sodium in amountsufiicient to saponify said fatty acid mixture at a temperature aboveabout 360 F. To the mixture about 10 to 20% by weight of Coastal paleoil and about 60 to of a 2000 SUS at F. Coastal red oil is added underconstant agitation and maintaining the temperature between about 360 to400 F. until a homogeneous mass is obtained. The hot grease is poured onto a suitable conveyor to a depth of not greater than and allowed tocool down to below 200 F. in less than 30 minutes by playing a coldstream of air on the hot grease.

Example IVB A'sodium soap grease was prepared in the manner describedunder Ex. IVA and divided into two parts, to one of which was addedbetween about 0.1 to 0.2% polyethylene glycol and to the other part ofthe grease was added between about 0.1 to 0.2% sodium naphthenate.

The remarkable improvement of greases of this invention over other typesof greases not containing soaps of this invention which can be furtherimproved by addition thereto of polyalkylene glycol or its derivativesor other antibleeding agents is illustrated in the table. Workedpenetration data are those obtained by the use of the proceduredescribed in A. S. T. M. Test D 217-38 T set forth in A. S. T. M.Standards (1942) using the U. S. Army-Navy Specification ANS-15 diskz325holes of inch diameter.

Worked ,stmkes Penetration Remrks Example IA. 60 268 Grease com letelyreversible on repeated remelt and recoo after 15 c cles and had no 300300 tendency :1 bleed. mg mg I y 10,000 'a'm 100,000 I (0 Example 13. 60300 Non-reversible and bleeds.

10,000 Example IIA 60 224 Samees Example IA.

10,000 325 100,000 Example 118 60 v 235 Same as Example 113.

v 10 388 m Example III 00 315 Com letely reversible, resistance toboiling water after immersion and kneading for 3 hours 338 .witoutchsngeineonshtenoyortexture. 1 Example 1V (Li soap inprism amlneraloil and at least, 5% lithium steerate 7 88 0) 330 Luon-reversibiamecimlly unstable and bleeds ly. Example V (Li 'soep)greese oomprls a mineraloil, at least 5% lithium steerate and a minor amount 0! less than 1%polyethylene g yoo v I v 300 Non-reversible,ml'sehiinieally unstable andbleeds freely.

Si olbecom fluid. F1235 I Fluid and teaming.

amuse Duringthecookingoithegreasatheremay be introduced therein smallamounts of any of the prior art soaps, and by small amounts is meantless than 2% for additional benefits. However, after a grease-of thepresent invention has been once cooked and cooled, said grease can beadmixed with anyv amount of a desirable soap grease. For example, theremay be incorporated into a cold lithium base grease of this inventionabout 1% to 70% of either aluminum soap grease or sodium soap grease.

To stabilize greases of the type described Hainst oxidation it isadvisable to add minor amounts of oxidation inhibitors to the. grease.Among the antioxidants which are efl'ective with grease composition ofthe type disclosed are: N-alkyl para phenylene diamine and condensedpolynuclear aromatic mono-amines. Such inhibitors are N-butylparaphenylene diamine, N-N- dibutyl para-phenylene diamine, etc. Alsoeifective as oxidation inhibitors are alpha or, beta naphthylamine,phenyl-alpha or beta naphthylamine, alpha-alpha, beta-beta, oralpha-beta dinaphthylamine, diphenylamine, tetra-methyl diamino diphenylmethane, petroleum alkyl phenols, and 2,4-ditertiary butyl B-methylphenol.

Corrosion inhibitors which are particularly applicable with compositionsof this invention are N-primary amines containing at least Band morethan 18 carbon atoms in the molecule such as hexylamine, octylamine.decylamine, dodecylamine, octadecylamine, heterocyclicnitrogen'containing organic compoundssuch as alkyl substitutedoxazolines and oxazoline salts of fatty acids.

Extreme pressureagents can be added to such grease and the preferredcomprise esters of phosphorus acids such as triaryl, alkylhydroxy, aryl.or aralkyl phosphates, thiophosphates or phosphites, etc., neutralaromatic sulfur compounds such as diaryl sulfldes'and polysulildes, e.g. diphenyl sulfide, dicresol sulfide, dibenzyl sulfide, methyl butyldiphenol sulfide, etc., diphenyl selenide and diselenide; decresolselenide and polyselenide. etc.: sulfurized fatty oils or esters offatty acids and monohydric alcohols, e. g. sperm oil, jojoba oil, etc.in which the sulfur is tightly bound: sulfurized bug-chain oleflnsobtained by dehydrogenation or cracking of wax: sulfurizedphosphorizedfatty oils, acids, esters and ketones, phosphorous acid esters havingsulfurized organic radicals, such as esters of phosphoric or phosphorusacids with hydroxy fatty acids: "chlorinated hydrocarbons such aschlorinated paraflins, aromatic hydrocarbons, terpenes,minerallubrieating oil, etc.: or chlorinated ester of fatty acidscontaining the chlorine in position other than alpha position.

10 manner fully described in applicant's co-pending application Ser. No.666,790 filed May 2, '1946. Essentially this comprises in coolinggreases in a rather rapid manner in the absence of any shearing stress.that is while the grease is mainwhile being carried along on the belt iscooled in a uniform fashion free from shearing stress. By cooling inthis manner, an unusually smooth grease is obtained which has a higherconsistency with less soap than a grease containing a greater amount ofsoap but cooled by convenient means.

Many modifications as to cooling can be made without departing from thescope or spirit of the invention. Thus the grease can be cooled on abelt moving at a controlled rate and the cooling medium directedcountercurrent to the flow of the grease, Also the thickness of thegrease layer should be controlled because with grease layers above aboutone inch in thickness. the rate of cooling becomes prohibitively low.Generally the thickness of a grease while being cooled should be between1 to /4" in thickness.

The length of a belt suitable for commercial grease production should beat least 100 it. long and moved at a speed of about 13 feet per minuteso that the total cooling time of a hot grease down to a Jelled massshould be in the neighborhood of about '7 to 10 minutes.

To improve the mechanical stability of the grease still further it canbe milled or homogenized after being quickly chilled. This can beaccomplished by breaking up the chilled mass in a screw conveyor andpumping it through'60 mesh screens into a suitable agitator such as atank equipped with agitators or a Cornell homogenizer where it is workeduntil constant penetration value is attained. The grease is then pumpedthrough mesh or flner screens to storage tanks or packaged.

Greases of this invention are applicable for general automotive use,they are excellent aircraft greases, and they are equally applicable forgeneral industrial use.

I claim as my invention:

1. A mechanically stable, thermally reversible non-bleeding lithium soapgrease comprising a Additional ingredients which can be added are Iabove about 800, volatilized parailln wax, un-- saturated polymerizedesters of fatty acids and major amount of a mineral lubricating oil,from about 5% to 25% of a lithium soap of a mixture comprising fromabout 10% to about 90% of 12- hydroxy stearic acid and from about 90% toi about 10% of a hydrogenated fish oil fatty acid.

monohydric alcohols, eta: oiliness agents-such as stearic and oleicacids and pour point depressors such as chlorinated naphthalinetofurther lower the pour point oi the lubricant.

The amount of the above additives can be added to grease composition ofthis invention in around about 0.01% to less than 10% by weight,

, and preferably 0.1 to 5.0% by weight.

Improved grease products of this inventioncan be'attained by quickcooling said inthe and from 0.1 to 1% of a polyalkylene glycol having anaverage molecular weight of between about 400 to about 7000.

2. A mechanically stable, thermally reversible non-bleeding lithium soapgrease comprising a 'major amount of a hydrocarbon oil, 5% to 25% oflithium soap derived from a mixture of from 10% to of a hydroxy fattyacid. and from 90% to 10% of a hydrogenatedfish oil fatty acid.

said acids each having at least 10 carbon atoms in the molecule and from0.01 to 0.5% of a polyalkylene glycol having ,anaverage molecular weightof between about 400 to about 7000.

3. A mechanically stable, thermally reversible non-bleeding sodium soapgrease comprising a major amount of a hydrocarbon oil, from betweenabout to 14% lithium soap derived from a mixture of from to 90% of ahydroxy fatty acid and-from 90% to 10% of a hydrogenated fish oil fattyacid, said acids each having atleast 10 carbon atoms in the molecule andfrom 0.01. to 0.5% of a polyalkylene glycol having an average molecularweight of between about 400 to about 7000.

4. A mechanically stable, thermally reversible grease compositioncomprising a major amount of a hydrocarbon oil and from 5% to 25% of asoap derived from a mixture of from 10% to 90%- of hydrogenated castoroil fatty acid, and from 90% to 10% of a hydrogenated fish oilfattyacid, said acids having at least 10 carbon atoms in the molecule.

6. A mechanically stable, thermally reversible grease compositioncomprising a major amount of a hydrocarbon oil, and from 5% to 25% of asoap derived from a mixture of from 10% to 90% of a 9,10-dihydroxystearic acid and from 90% to 10% of a hydrogenated flsh oilfatty acid,said acids having at least 10 carbon atoms in the molecule.

7. A mechanically stable, thermally reversible lubricating greasecomposition comprising a major amount of -a hydrocarbon oil and from 5%to 25% of a soap derived from a mixture of from 10% to 90% of l2-hydroxystearic acid and from 90% to 10% of a hydrogenated fish oil fatty acid,said acids having at least 10 carbon atoms in the molecule.

8. A mechanically stable, thermally reversible of a hydrogenated fishoil fatty acid, heating said mineral lubricating oil and soap mixture toa temperature of between about 370 to about 450 F., adding thereto lessthan 1.0% of a polyalkylene polyhydroxy polymeric compound from theclass consisting of polymeric polyalkylene glycol, ether derivative ofpolymeric polylakylene glycol and ester derivative of polymericpolyalkylene glycol and cooling said grease in layers of from about A;inch to about 1 inch in thickness at a rate sufficient for said greaseto cool to a gel state in less than 30 minutes.

12. A process of preparing lithium soap grease comprising admixing amajor amount of mineral lubricating oil with from 5% to of lithium soapderived from a mixture of from 10% to 90% of 9,10-dihydroxy stearic acidand from 90% to 10% of a hydrogenated fish oil fatty acid, heating saidmineral lubricating oil and soap mixture to a temperature of betweenabout 370 to about 450 F., adding from 0.1 to 1.0% of a polyalkylenepolyhydroxy compound from the class consisting of polyalkylene glycol,ether derivative of polyalkylene glycol and ester derivative ofpolyalkylene glycol and cooling said grease in layers of from about A;inch to about 1 inch in thickness at a rate sufficient for said greaseto cool to a gel state in less than minutes.

13. A process of preparing lithium soap grease comprising admixing amajor amount of mineral lubricating oil with from 5% to 25% of lithiumlubricating grease composition comprising a major amount of ahydrocarbon oil and a minor amount of not less than 5% soap derived froma mixture of from 10 to 90% of a hydroxy fatty acid and from 90 to 10%of a hydrogenated fish oil fatty acid, said acids each having at least10 carbon atoms in the molecule.

9. A mechanically stable, thermally reversible lubricating greasecomposition comprising a major amount of a hydrocarbon oil, and a minoramount of not less than 5% soap derived from a mixture of from 10% to90% of a hydroxy fatty acid and from 90% to 10% of a hydrogenated fattyoil said saponiflable materials each having 'at least 6 carbon atoms inthe molecule.

10. A mechanically stable, thermally reversible soap derived from amixture of from 10% to 90% of hydrogenated castoroil fatty acid and from90% to 10% of a hydrogenated fish oil fatty acid. heating said minerallubricating oil and soap mixture to a temperature of between about370 toabout 450 F., adding from 0.1 to 1.0% of a polyalkylene polyhydroxycompound from the class consisting of polyalkylene glycol, etherderivative of polyalkylene glycol and ester derivative of polyalkyleneglycol and cooling said grease in layers of from about inch to aboutlinch in thickness at a rate suflicient for said grease to cool to a gelstate in less than 30 minutes.

14. A process of preparing lithium soap grease comprising admixing amajor amount of mineral lubricating oil with a minor amount sumcient toform a grease of lithium soap derived from a mixture of from 10% to 90%of a hydroxy fatty acid and from 90% to 10% of a hydrogenated fish oilfatty acid, said fatty acids each having at least 6 carbon atoms in themolecule, heating said non-bleeding lubricating grease compositioncomprising a major amount of a hydrocarbon oil,

and a'minor amount of not less than 5% soap derived from a mixture offrom 10% to 90% of a hydroxy fatty acid and from 90% to 10% of ahydrogenated fatty acidsaid saponiflable mate- 1 rials each havingat-least 6 carbon atoms inthe molecule.

, 11. A process of preparing lithium soap grease comprising admixing amajor amount of mineral lubricating oil with from 5% to 25% of lithiumsoap derived from a mixture of from 10% to 90% of lz-hydroxy stearicacid and from 90 to 10% .said grease 'to cool to a gel state minerallubricating oil and soap mixture to a temperature of between about 370to about 450' F., adding from 0.1 to 1.0% of a polyalkylene polyhydroxycompound from the class consisting of polyalkylene glycol, etherderivative of polyalkylene glycol and ester ,derivativeof polyalkyleneglycol and cooling said grease in layers of less than; 1 inch inthickness at a ratesufiicient for in less than 30 minutes.

15, A process of preparing sodium soap grease comprising admixing amajor amount of mineral lubricating oil with a minor amount sumcient toform a grease of sodium soap derived from a mixture of from 10% to 90%of a hydroxy fatty acid and from 90% to 10% of. a'hydrogenated fish oil6 carbon atoms in the molecule, heating said mineral lubricating oil andsoap mixture to a temperature of between-about 370 to. about 450 F.,adding from 0.1 to.1.0% of a polyalkylene polyhydroxy compound from theclass consisting of polyalkylene glycol, ether derivative of polyamuseto 10% of a hydrogenated flsh oil fatty acid, said fatty acids eachhaving at least 6 carbon atoms in the molecule, heating said minerallubricating oil and soap mixture to a grease forming elevatedtemperature, adding from 0.1 to 1.0% of a poly alkylene polyhydroxycompound from the class consisting of polyalkylene glycol, etherderivative .of polyalkylene glycol and ester. derivative of poiyalkyleneglycol and cooling said grease in layers of less than 1 inch inthickness at a rate sumcient for said grease to cool to a gel state inless than 30 minutes.

17. A process of preparing grease comprising admixing a majoramount ofmineral lubricating oil with a minor amount suilicient to form a greaseof soap derived from a mixture of from 10% to 90% of a hydroxy fattyacid and from 90% to 10% of a hydrogenated fish oil fatty acid, saidfatty acids each having at least 6 carbon atoms in the molecule, heatingsaid mineral lubricating oil and soap mixture to a grease formingelevated temperatureand cooling said .grease'thereafter in layers ofless than 1 inch in thickness at a rate sufllcient for said grease tocool to a gel state in less than 30 minuta.

18. A mechanically stable,'thermally reversible lubricating greasecomposition comprising a maior amount of alubricating oil and from 5% to25% of a soap derived from a mixture of from to 90% of a hydroxy fattyacid and from 90% to 10% of a hydrogenated fatty acid, said saponiflablematerials each having at least 6 car bon atoms in the molecule.

19. A mechanically stable, thermally reversible. non-bleeding greasecomprising a major amount of a lubricating oil, from 5% to 25% of a soapderived from a mixture of from 10% to 25% of a soap derived from amixture of from 10% to 90% of a hydroxy fatty acid and from 90% to 10%of a hydrogenated fatty acid, said saponiflable materials each having atleast 8 carbon atoms in the molecule, and from 0.01% to 1% of a:polyalkylene poly ydroxy compound from the class consisting ofpolyalkylene lycol, ether derivative of polyalkylene glycol and esterderivative of polyalkylene glycol.

20. A process of preparing grease comprising admixing a major amount oflubricating oil with from 5% to 25% of a soap derived from a mixture offrom 10% to of a hydroxy fatty acid and from 90% to 10% of ahydrogenated fatty acid, said saponiflable materials each having atleast 6 carbon atoms in the molecule, heating said lubricating oil andsoap mixture to a grease forming elevated temperature and cooling saidgrease thereafter in layers of less than 1 inch in thickness at a ratesumcient for said grease to cool to a gel state in less than 30 minutes.

21. A process of preparing grease comprising admixing a major amount oflubricating oil with from 5% to 25% of a soap derived from a mixture offrom 10% to 90% of a hydroxy fatty acid and from 90% to 10% of ahydrogenated fatty acid, said saponifiable materials each having atleast 6 carbon atoms in the molecule, heating said lubricating oil andsoap to a grease forming elevated temperature, adding from 0.01% to 1%of a polyalkylene polyhydroxy compound from the class consistingofpolyalkylene glycol, ether derivative of polyalkylene glycol and esterderivative of polyalkylene glycol, and cooling said grease in layers ofless than 1 inch in thickness at a rate sufllcient for said grease tocool to a gel state in less than 30 minutes.

ARNOLD. A. BONDI.=

REFERENCES CITED The following references are of record in the Bax Aug.27, 1946 Certificate of Correction Patent No. 2,475,589 July 12; 1949ARNOLD A. BONDI It is hereby certified that errors appear in the printedspecification of the above numbered patent requiring correction asfollows:

Column 11, lines 48 and 49, lines 56 and 57, and line 65, for a minoramount of not less than 5% read from 5% to 25% of a column 13, lines 8and 9, strike out the words sufiicient to form a grease lines 25 and 26,for a minor amount suificient to form a grease read from 5% to 25% andthat the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the casein the PatentOffice.

Signed and sealed this 2nd day of May, A. D. 1950.

THOMAS F. MURPHY,

Assistant Uommiasianer of Patents.

